I have been playing with Ardour for about a week now and find it intriguing. I am looking for recommendations for a multiple input sound card that plays well with Linux. If i were to try to build a multitrack studio (just for personal use, not a big professional rig), what are some recommendations for hardware and software?

For hardware, apart form the M-audio delta's and the RME Hammerfall series documented on the ardour website an audigy soundblaster is good enough for personal use. The main requirement is good alsa support. Jack (as you probably know) at http://jackit.sourceforge.net is a must.